Paperboard caskets are used for their relatively low cost of manufacture and for their inflammability properties when used for cremation. Although a large market exists for such caskets, the corrugated board structure thereof must be made to look and perform like wood in order for the casket to enjoy a market acceptance.
A number of paperboard caskets has been developed in the past and has been used with varying degrees of success. In that respect, examples of paperboard casket shells are illustrated in the following documents. In these examples, the casket shells are made of corrugated paperboard folded from blanks. In many cases, the corrugated paperboard is reinforced with wood strips at stress concentration areas. These are the types of caskets, generally, that are of interest herein. These examples are as follows:
U.S. Pat. No. 3,220,080 issued on Nov. 30, 1965 to R. E. Connelly; PA0 U.S. Pat. No. 3,574,906 issued on Apr. 13, 1971 to R. Rittenhouse; PA0 U.S. Pat. No. 3,729,786 issued on May 1, 1973 to R. T. Walding; PA0 U.S. Pat. No. 4,063,337 issued on Dec. 20, 1977 to A. S. Havey III; PA0 U.S. Pat. No. 4,151,630 issued on May 1, 1979 to A. S. Havey; PA0 U.S. Pat. No. 4,156,956 issued on Jun. 5, 1979 to R. J. Partridge et al.; PA0 U.S. Pat. No. 4,170,054 issued on Oct. 9, 1979 to A. Ruffner et al.; PA0 U.S. Pat. No. 4,176,431 issued on Dec. 4, 1979 to A. S. Havey III; PA0 U.S. Pat. No. 4,209,880 issued on Jul. 1, 1980 to S. O. Lidholm; PA0 U.S. Pat. No. 4,399,596 issued on Aug. 23, 1983 to H. W. Parlour et al.; PA0 U.S. Pat. No. 4,730,370 issued on Mar. 15, 1988 to B. E. Elder; PA0 U.S. Pat. No. 4,854,018 issued on Aug. 8, 1989 to M. G. Von Bratt; PA0 U.S. Pat. No. 4,891,869 issued on Jan. 9, 1990 to D. W. Nutting; PA0 U.S. Pat. No. 4,967,455 issued on Nov. 6, 1990 to B. E. Elder; PA0 U.S. Pat. No. 5,035,032 issued on Jul. 30, 1991 to D. W. Nutting; PA0 U.S. Pat. No. 5,111,559 issued on May 12, 1992 to J. G. Mohr et al.; PA0 U.S. Pat. No. 5,307,545 issued on May 3, 1994 to D. J. Stoltz; PA0 U.S. Pat. No. 5,353,484 issued on Oct. 11, 1994 to S. D. Woedl et al.; PA0 U.S. Pat. No. 5,454,141 issued on Oct. 3, 1995 to L. D. Ozbun et al.; PA0 U.S. Pat. No. 5,586,679 issued on Dec. 24, 1996 to B. M. Thomas; PA0 U.S. Pat. No. 5,740,592 issued on Apr. 21, 1998 to C. K. Lau; PA0 U.S. Pat. No. 5,771,548 issued on Jun. 30, 1998 to K. T. Jenkins; PA0 Canadian applications for patent: PA0 CA 2,150,134 filed on Sep. 6, 1994 by A. Gillard et al.; PA0 CA 2,154,009 filed on Jul. 17, 1995 by Y. Beauregard; PA0 CA 2,155,723 filed on Aug. 9, 1995 by G. Huot.
It is believed that aside from general appearance, selling price and ultimate tensile strength, a first requirement by the funeral industry regarding paperboard caskets is that a casket shell must be relatively stiff to resist to some degrees, torsional stresses when lifted unevenly. A second preferred requirement by the funeral industry is believed to be that the corners of the casket shell must retain their squareness under dynamic stresses. Similarly, it is believed that a third preferred requirement by the funeral industry is that the shape of the casket shell must remain firm after several liftings and manipulations under design loading conditions. Finally, several other preferred requirements by the funeral industry are believed to be that all corners and edges of a paperboard casket shell must be sharp to better imitate a wood structure; that the side and end walls of the casket shell should have a same and uniform thickness; that a decorative material covering the shell should be joined along a vertical median line on one or both ends of the casket shell to better imitate a sewn scam in a single piece of fabric.
The paperboard caskets of the prior art are believed to be deficient at least one of the above preferred requirements, and it is this reason basically that has contributed to the development of a market demand for a better paperboard casket shell capable of resisting severe loading conditions and to better imitate a high quality wood structure.